| A MicroInjection Molding Test Bed (MIMTB) that can generate high injection rates and forces has been developed to increase the productivity of research in the polymeric flow behavior at the microscale and the manufacturing of micro-scale plastic parts economically. The MIMTB uses impact energy to generate an injection force profile that can be accurately controlled in both magnitude and duration.; Current results show that the MIMTB is capable of producing maximum injection forces of at least 69,000 psi with hold times of as little as 6 microseconds. Repeatability tests showed that a force of average magnitude 3,340 psi and duration 7 ms produced a standard deviation of +/- 148 psi and 0.165 milliseconds, respectively. The MIMTB can mold parts successfully from raw material in quantities as low as 3.7 milligrams and has successfully produced parts weighing as little as 0.39 milligrams. A number of micro-molds for this device were fabricated using traditional CNC milling techniques. Preliminary experiments were conducted to determine the solidification time of micro-scale parts, resulting in 2.3, 0.2, and 0.1 seconds for center gated disc of 1143, 254, and 127 mum thickness, respectively. |
